unicorn/glib_compat/grand.c

385 lines
10 KiB
C

/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/* Originally developed and coded by Makoto Matsumoto and Takuji
* Nishimura. Please mail <matumoto@math.keio.ac.jp>, if you're using
* code from this file in your own programs or libraries.
* Further information on the Mersenne Twister can be found at
* http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
* This code was adapted to glib by Sebastian Wilhelmi.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/*
* MT safe
*/
#define _CRT_RAND_S
#include <math.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#ifndef _MSC_VER
#include <unistd.h>
#include <sys/time.h>
#else
#include <windows.h>
#endif
#include "grand.h"
#include "gmem.h"
#include "gmessages.h"
#define G_USEC_PER_SEC 1000000
#if defined(__MINGW64_VERSION_MAJOR) || defined(_WIN32)
errno_t rand_s(unsigned int* randomValue);
#endif
#define G_GINT64_CONSTANT(val) (val##L)
/* Period parameters */
#define N 624
#define M 397
#define MATRIX_A 0x9908b0df /* constant vector a */
#define UPPER_MASK 0x80000000 /* most significant w-r bits */
#define LOWER_MASK 0x7fffffff /* least significant r bits */
/* Tempering parameters */
#define TEMPERING_MASK_B 0x9d2c5680
#define TEMPERING_MASK_C 0xefc60000
#define TEMPERING_SHIFT_U(y) (y >> 11)
#define TEMPERING_SHIFT_S(y) (y << 7)
#define TEMPERING_SHIFT_T(y) (y << 15)
#define TEMPERING_SHIFT_L(y) (y >> 18)
struct _GRand
{
guint32 mt[N]; /* the array for the state vector */
guint mti;
};
static guint get_random_version (void)
{
static gsize initialized = FALSE;
static guint random_version;
if (!initialized)
{
// g_warning ("Unknown G_RANDOM_VERSION \"%s\". Using version 2.2.", version_string);
random_version = 22;
initialized = TRUE;
}
return random_version;
}
/**
* g_rand_set_seed:
* @rand_: a #GRand
* @seed: a value to reinitialize the random number generator
*
* Sets the seed for the random number generator #GRand to @seed.
*/
void g_rand_set_seed (GRand *rand, guint32 seed)
{
g_return_if_fail (rand != NULL);
switch (get_random_version ())
{
case 20:
/* setting initial seeds to mt[N] using */
/* the generator Line 25 of Table 1 in */
/* [KNUTH 1981, The Art of Computer Programming */
/* Vol. 2 (2nd Ed.), pp102] */
if (seed == 0) /* This would make the PRNG produce only zeros */
seed = 0x6b842128; /* Just set it to another number */
rand->mt[0]= seed;
for (rand->mti=1; rand->mti<N; rand->mti++)
rand->mt[rand->mti] = (69069 * rand->mt[rand->mti-1]);
break;
case 22:
/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
/* In the previous version (see above), MSBs of the */
/* seed affect only MSBs of the array mt[]. */
rand->mt[0]= seed;
for (rand->mti=1; rand->mti<N; rand->mti++)
rand->mt[rand->mti] = 1812433253UL *
(rand->mt[rand->mti-1] ^ (rand->mt[rand->mti-1] >> 30)) + rand->mti;
break;
default:
// g_assert_not_reached ();
break;
}
}
/**
* g_rand_new_with_seed:
* @seed: a value to initialize the random number generator
*
* Creates a new random number generator initialized with @seed.
*
* Returns: the new #GRand
**/
GRand* g_rand_new_with_seed (guint32 seed)
{
GRand *rand = g_new0 (GRand, 1);
g_rand_set_seed (rand, seed);
return rand;
}
/**
* g_rand_set_seed_array:
* @rand_: a #GRand
* @seed: array to initialize with
* @seed_length: length of array
*
* Initializes the random number generator by an array of longs.
* Array can be of arbitrary size, though only the first 624 values
* are taken. This function is useful if you have many low entropy
* seeds, or if you require more then 32 bits of actual entropy for
* your application.
*
* Since: 2.4
*/
void g_rand_set_seed_array (GRand *rand, const guint32 *seed, guint seed_length)
{
guint i, j, k;
g_return_if_fail (rand != NULL);
g_return_if_fail (seed_length >= 1);
g_rand_set_seed (rand, 19650218UL);
i=1; j=0;
k = (N>seed_length ? N : seed_length);
for (; k; k--)
{
rand->mt[i] = (rand->mt[i] ^
((rand->mt[i-1] ^ (rand->mt[i-1] >> 30)) * 1664525UL))
+ seed[j] + j; /* non linear */
rand->mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
i++; j++;
if (i>=N)
{
rand->mt[0] = rand->mt[N-1];
i=1;
}
if (j>=seed_length)
j=0;
}
for (k=N-1; k; k--)
{
rand->mt[i] = (rand->mt[i] ^
((rand->mt[i-1] ^ (rand->mt[i-1] >> 30)) * 1566083941UL))
- i; /* non linear */
rand->mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
i++;
if (i>=N)
{
rand->mt[0] = rand->mt[N-1];
i=1;
}
}
rand->mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
}
/**
* g_rand_new_with_seed_array:
* @seed: an array of seeds to initialize the random number generator
* @seed_length: an array of seeds to initialize the random number
* generator
*
* Creates a new random number generator initialized with @seed.
*
* Returns: the new #GRand
*
* Since: 2.4
*/
GRand *g_rand_new_with_seed_array (const guint32 *seed, guint seed_length)
{
GRand *rand = g_new0 (GRand, 1);
g_rand_set_seed_array (rand, seed, seed_length);
return rand;
}
gint64 g_get_real_time (void)
{
#if defined(unix) || defined(__unix__) || defined(__unix) || defined (__MINGW32__) || defined(__APPLE__)
struct timeval r;
/* this is required on alpha, there the timeval structs are ints
* not longs and a cast only would fail horribly */
gettimeofday (&r, NULL);
return (((gint64) r.tv_sec) * 1000000) + r.tv_usec;
#else
FILETIME ft;
guint64 time64;
GetSystemTimeAsFileTime (&ft);
memmove (&time64, &ft, sizeof (FILETIME));
/* Convert from 100s of nanoseconds since 1601-01-01
* to Unix epoch. This is Y2038 safe.
*/
time64 -= G_GINT64_CONSTANT (116444736000000000);
time64 /= 10;
return time64;
#endif
}
/**
* g_rand_new:
*
* Creates a new random number generator initialized with a seed taken
* either from `/dev/urandom` (if existing) or from the current time
* (as a fallback).
*
* On Windows, the seed is taken from rand_s().
*
* Returns: the new #GRand
*/
GRand *g_rand_new (void)
{
guint32 seed[4];
#if defined(unix) || defined(__unix__) || defined(__unix) || defined(__APPLE__)
static gboolean dev_urandom_exists = TRUE;
if (dev_urandom_exists)
{
FILE* dev_urandom;
do
{
dev_urandom = fopen("/dev/urandom", "rb");
}
while (dev_urandom == NULL && errno == EINTR);
if (dev_urandom)
{
int r;
setvbuf (dev_urandom, NULL, _IONBF, 0);
do
{
errno = 0;
r = fread (seed, sizeof (seed), 1, dev_urandom);
}
while (errno == EINTR);
if (r != 1)
dev_urandom_exists = FALSE;
fclose (dev_urandom);
}
else
dev_urandom_exists = FALSE;
}
if (!dev_urandom_exists)
{
gint64 now_us = g_get_real_time ();
seed[0] = now_us / G_USEC_PER_SEC;
seed[1] = now_us % G_USEC_PER_SEC;
seed[2] = getpid ();
seed[3] = getppid ();
}
#else /* G_OS_WIN32 */
/* rand_s() is only available since Visual Studio 2005 and
* MinGW-w64 has a wrapper that will emulate rand_s() if it's not in msvcrt
*/
#if (defined(_MSC_VER) && _MSC_VER >= 1400) || defined(__MINGW64_VERSION_MAJOR)
gint i;
for (i = 0; i < 4;/* array size of seed */ i++) {
rand_s(&seed[i]);
}
#else
#warning Using insecure seed for random number generation because of missing rand_s() in Windows XP
GTimeVal now;
g_get_current_time (&now);
seed[0] = now.tv_sec;
seed[1] = now.tv_usec;
seed[2] = getpid ();
seed[3] = 0;
#endif
#endif
return g_rand_new_with_seed_array (seed, 4);
}
/**
* g_rand_int:
* @rand_: a #GRand
*
* Returns the next random #guint32 from @rand_ equally distributed over
* the range [0..2^32-1].
*
* Returns: a random number
*/
guint32 g_rand_int (GRand *rand)
{
guint32 y;
static const guint32 mag01[2]={0x0, MATRIX_A};
/* mag01[x] = x * MATRIX_A for x=0,1 */
g_return_val_if_fail (rand != NULL, 0);
if (rand->mti >= N) { /* generate N words at one time */
int kk;
for (kk = 0; kk < N - M; kk++) {
y = (rand->mt[kk]&UPPER_MASK)|(rand->mt[kk+1]&LOWER_MASK);
rand->mt[kk] = rand->mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
}
for (; kk < N - 1; kk++) {
y = (rand->mt[kk]&UPPER_MASK)|(rand->mt[kk+1]&LOWER_MASK);
rand->mt[kk] = rand->mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
}
y = (rand->mt[N-1]&UPPER_MASK)|(rand->mt[0]&LOWER_MASK);
rand->mt[N-1] = rand->mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];
rand->mti = 0;
}
y = rand->mt[rand->mti++];
y ^= TEMPERING_SHIFT_U(y);
y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
y ^= TEMPERING_SHIFT_L(y);
return y;
}